WO2015055778A1

WO2015055778A1 - Method and apparatus for detecting location of smart key

Info

Publication number: WO2015055778A1
Application number: PCT/EP2014/072254
Authority: WO
Inventors: Sunghoon Lee
Original assignee: Continental Automotive Gmbh
Priority date: 2013-10-16
Filing date: 2014-10-16
Publication date: 2015-04-23
Also published as: KR101430702B1

Abstract

Disclosed herein is a method and apparatus for detecting a location of a smart key. The method includes: detecting, by a smart key controller, a smart key located within a reference distance from a vehicle; when an authenticated smart key located within the reference distance from the vehicle is detected, sending an LF signal including RSSI (Received Signal Strength Indication) information and data for identification to the detected smart key; and receiving an RF (radio frequency) response signal including RSSI measurements in response to the LF signal.

Description

METHOD AND APPARATUS FOR DETECTING LOCATION OF SMART KEY

BACKGROUND

1. Technical Field

The present invention relates to a method and apparatus for detecting a location of a smart key, and more particularly, to a method and apparatus for more accurately detecting a location of a smart key placed around a vehicle.

2. Description of the Related Art

With the development of electronic control technology applied to vehicles, there have been developed technologies of using a smart key to automatically open/close doors of a vehicle, start a vehicle, and so on. Such technologies enable a driver carrying a smart key to open/close the door and start an engine, thereby maximizing driver convenience.

Recently, a handsfree-tailgate function has been developed to automatically open a tailgate when a driver carrying a smart key approaches surrounding regions of a trunk or the tailgate.

That is, when a driver approaches a vehicle with the handsfree-tailgate function previously set by the driver and an authenticated smart key is detected around the vehicle through periodic search for surrounding regions of the vehicle, the tailgate is opened without any manipulation of the driver, thereby enhancing driver convenience.

In addition, as one of functions applied to luxury vehicles, a welcome light function has been developed.

That is, when a driver carrying a smart key exits a vehicle and moves away from the vehicle, a headlamp or a lamp installed in a door is turned on and directed toward a moving direction of the driver in accordance with locations of the smart key, thereby assisting the driver in moving safely.

Further, the welcome light function is equally applied even when a driver approaches the vehicle as well as when the driver exits and moves away from the vehicle. A background technique of the present invention is disclosed in Korean Patent Publication No. 2013-0089069 (published on August 9, 2013 and entitled "System for Searching for Smart Key for vehicles").

To normally operate such a smart key as intended by a driver, it is necessary to achieve correct authentication of the smart key approaching the vehicle and accurate determination of a location of the smart key.

Particularly, in order to accurately determine the location of the smart key, the location of the smart key must be frequently detected by sending and receiving signals between a smart key controller and the smart key in a shorter cycle.

BRIEF SUMMARY

The present invention has been conceived to satisfy the aforementioned requirements and it is an aspect of the present invention to provide a method and apparatus for more accurately detecting a location of a smart key by reducing a signal transception frequency through transmission and reception of a signal including minimized information when it is determined that an authenticated smart key is placed around a vehicle.

In accordance with one aspect of the present invention, a method for detecting a location of a smart key includes; detecting, by a smart key controller, a smart key located within a reference distance from a vehicle; when an authenticated smart key located within the reference distance from the vehicle is detected, sending an LF (Low frequency) signal including RSSI (Received Signal Strength Indication) information and data for identification to the detected smart key; and receiving an RF (radio frequency) response signal including RSSI measurements in response to the LF signal.

Detecting a smart key located within a reference distance from a vehicle may include: sending an LF signal including RSSI information and encrypted data around the vehicle; and receiving an RF response signal including RSSI measurements and data corresponding to the encrypted data in response to the LF signal.

The data for identification may comprise data including information for the smart key controller to identify the smart key, and the encrypted data may comprise data including information for the smart key controller to perform an authentication procedure with regard to the smart key.

In sending the LF signal, the smart key controller may send the LF signal including masking information for specifying a smart key such that only the detected smart key can issue a response.

The method may include returning to sending the LF signal when a predetermined reference time has elapsed after sending the LF signal.

The method may include returning to sending the LF signal when the RF response signal is received from the authenticated smart key before the predetermined reference time has elapsed.

The method may further include determining whether the authenticated smart key is present within the reference distance from the vehicle after receiving the RF response signal and returning to sending the LF signal when the authenticated smart key is present within the reference distance.

In accordance with another aspect of the present invention, an apparatus for detecting a location of a smart key includes: a communication unit which communicates with a smart key; and a smart key controller for sending an LF (low frequency) signal including received signal strength indication (RSSI) information and data for identification to a detected authenticated smart key and for receiving an RF (radio frequency) response signal including RSSI measurements through the communication unit when the authenticated smart key located within a reference distance from a vehicle is detected through the communication unit.

The authenticated smart key located within the reference distance from the vehicle may be detected as the communication unit sends an LF signal including RSSI information and encrypted data to surrounding regions of the vehicle and receives an RF response signal including RSSI measurements and data corresponding to the encrypted data in response to the LF signal.

The smart key controller may be adapted to send the LF signal including masking information for specifying a smart key such that only the detected smart key can issue a response. According to the present invention, time taken in sending and receiving a signal for detecting a location of a smart key is minimized, whereby a path of the smart key can be more accurately detected.

Further, the present invention enables correct execution of a subsequent control command by correctly determining a driver intention about whether to enter or pass by a vehicle based on accurate detection of the path of the smart key.

BRIEF DESCRIPTION OF THE DRAWINGS The above and other aspects, features and advantages of the invention will become apparent from the following description of exemplary embodiments given in conjunction with the accompanying drawings, in which:

Fig. 1 is a block diagram of an apparatus for detecting a location of a smart key according to one embodiment of the present invention;

Fig. 2 shows a structure of data sent and received in the apparatus for detecting a location of a smart key according to the embodiment of the present invention;

Fig. 3 shows a plurality of slots corresponding to responses of a plurality of smart keys; and

Fig. 4 is a flowchart of a method for detecting a location of a smart key according to one embodiment of the present invention.

DETAILED DESCRIPTION

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. It should be noted that the drawings are not to precise scale and may be exaggerated in thickness of lines or size of components for descriptive convenience and clarity only. In addition, the terms used herein are defined by taking functions of the present invention into account and can be changed according to user or operator custom or intention. Therefore, definition of the terms should be made according to the overall disclosure set forth herein. Fig. 1 is a block diagram of an apparatus for detecting a location of a smart key according to the embodiment of the present invention.

Fig. 2 shows a structure of data sent and received in the apparatus for detecting a location of a smart key according to the embodiment of the present invention.

Referring to Figs. 1 and 2, an apparatus for detecting a location of a smart key according to one embodiment of the present invention includes a communication unit 10, a smart key controller 20, a memory 30, and a timer 40.

The communication unit 10 is configured to communicate with a smart key 1 , and receives a driver control command or a signal for detecting the location of the smart key 1 through communication with the smart key 1.

Specifically, the communication unit 10 communicates with the smart key 1 in such a manner that an LF (low frequency) signal is sent to the smart key 1 through an LF transmitter (not shown) and RF (radio frequency) response signals is received from the smart key 1 through an RF receiver (not shown) in response to the LF signal.

The smart key controller 20 controls the communication unit 10 to communicate signals with the smart key 1 around a vehicle, thereby authenticating the smart key 1 and determining the location of the smart key 1.

Specifically, the smart key controller 20 detects the smart key 1 located within a reference distance from the vehicle and communicates the signals with the detected smart key 1 , thereby accurately determining the location of the corresponding smart key 1.

The reference distance refers to a distance where communication between the smart key controller 20 and the smart key 1 can be performed for controlling the vehicle through the smart key 1, and may be set differently according to signal generation performance of the smart key controller 20 and the smart key 1.

In particular, the smart key controller 20 according to one embodiment of the invention sends LF signal including received signal strength indication (RSSI) information and encrypted data to surrounding regions of the vehicle and receives RF response signals including RSSI measurements about the strength of RSSI and data corresponding to the encrypted data, thereby detecting an authenticated smart key 1 located within the reference distance from the vehicle. That is, the smart key controller 20 sends the RSSI information and determines a distance from the smart key 1 according to the RSSI measurements of the smart key 1 that receives the RSSI information.

In addition, the smart key controller 20 sends predetermined encrypted data and confirms whether the smart key 1 entering the reference distance from the vehicle is an authenticated smart key based on the data received corresponding to the encrypted data.

Further, in this embodiment, after the authenticated smart key 1 located within the reference distance from the vehicle is detected, the smart key controller 20 sends the LF signal including only minimum data and RSSI information, and receives the RF response signal including only the RSSI measurements, thereby detecting the location of the smart key 1 in a short cycle.

In other words, unlike a conventional case where the LF signal including the encrypted data are continuously sent after detection of the authenticated smart key, in the method according to this embodiment, the LF signal of data including the minimum information for identifying the smart key 1 is sent after detection of the authenticated smart key 1.

The data for identification refers to data including information for identifying the smart key 1 , and the encrypted data refers to data including information for performing an authentication procedure with regard to the smart key 1. The data for identification is shorter than the encrypted data and it is thus possible to reduce time taken in sending and receiving the data.

Since the smart key controller 20 receives the RF response signal including only the RSSI measurements from the smart key 1 , it is possible to achieve significant reduction in time for sending and receiving the signal for detecting the location of the smart key 1.

Referring to Fig. 2, a structure of data sent and received between the smart key controller 20 and the smart key 1 according to one embodiment of the present invention is as follows. Section Tl shows a structure of data sent and received by the smart key controller 20 for detecting the authenticated smart key 1 located within the reference distance from the vehicle, and section T2 shows a structure of data sent and received by the smart key controller 20 for detecting the location of the smart key 1. As shown in Fig. 2, although section Tl and section T2 show relative lengths of the data for authenticating the smart key 1 and the data for detecting the location of the smart key 1, these sections do not show a ratio of absolute lengths.

As described above, in section Tl, the smart key controller 20 sends the LF signal including the RSSI information and the encrypted data to determine whether the smart key

1 located within the reference distance from the vehicle is the authenticated smart key 1, and receives the RF response signal including the RSSI measurements and the data corresponding to the encrypted data from the smart key 1.

If the detected smart key is determined as the authenticated smart key 1 , in section T2, the smart key controller 20 sends the LF signal including the RSSI information and the data for identification including only the minimum information for identifying the smart key 1, and receives the RF signal including the RSSI measurements from the smart key 1.

In this embodiment, since the encrypted data for determining the authenticated smart key 1 is longer and greater than the data for identification, only the simplified signals are sent and received after the smart key 1 is authenticated, thereby accurately detecting the location of the smart key 1 in a short cycle.

Fig. 3 shows a plurality of slots corresponding to responses of a plurality of smart keys.

A driver may register and use a plurality of smart keys 1 with regard to a vehicle. When signals are received from the plurality of smart keys 1, the signals may be distorted and thus cause an error in authentication of the smart keys 1 or in determination of locations thereof. Thus, the smart key controller 20 receives RF response signals from the respective smart keys 1 in units of time divided as shown in Fig. 3.

Specifically, a common time slot is a section where all the smart keys 1 respond to LF signal, and the next slots are sections where the smart keys 1 alternately issue responses in accordance with predetermined order.

That is, since the smart key controller 20 has to wait for responses from all of the plurality of registered smart keys 1 during assigned time, the procedure is retarded.

Accordingly, in this embodiment, the smart key controller 20 sends LF signal additionally including masking information for specifying a smart key 1 such that only a detected authenticated smart key 1 can issue a response after the authenticated smart key 1 is detected, thereby minimizing the communicating frequency of signals with the smart key 1.

That is, in this embodiment, even though the plurality of smart keys 1 enters a reference distance from a vehicle, the LF signal including the masking information is sent to allow only the first-authenticated smart key 1 to issue a response, whereby the smart key controller 20 can receive only the RF response signal from the corresponding smart key 1.

Therefore, the smart key controller 20 sends the LF signal and then sends the LF signal including RSSI information, data for identification and the masking information after a predetermined reference time elapses.

The reference time refers to time taken until the smart key 1 sends the RF response signal from time of receiving the LF signal and may vary depending upon the reference distance, i.e. a communicative distance between the smart key 1 and the smart key controller 20.

Since such a procedure is repeated while the smart key 1 is present within the reference distance from the vehicle, it is possible to quickly determine a correct location of the smart key 1.

In this embodiment, the smart key controller 20 may send the LF signal including the RSSI information, the data for identification and the masking information again upon receiving the RF response signal from the smart key 1 corresponding to the masking information even before the reference time elapses.

That is, in this embodiment, when the RF response signal is received during only the reference time or more quickly than the reference time, a simplified LF signal is sent as soon as the RF response signal is received. Therefore, it is possible to reduce time taken in sending and receiving signals.

The memory 30 stores encryption information about authentication of the smart key 1 and information for identifying the plurality of smart keys 1. The smart key controller 20 compares the data of the received RF response signal with the information stored in the memory 30 so as to authenticate the smart key 1 and confirm registration information of the corresponding smart key 1. The timer 40 measures time taken until the smart key controller 20 receives the RF response signal after sending the LF signal. When a predetermined reference time has elapsed, the smart key controller 20 sends the LF signal again and thus quickly communicates the signal with the smart key 1.

Referring to Fig. 4, in a method for detecting a location of a smart key according to one embodiment of the present invention, the smart key controller 20 first detects a smart key 1 located within a reference distance from a vehicle.

Specifically, the smart key controller 20 sends LF signal including RSSI information and encrypted data to surrounding regions of the vehicle (S10), and receives RF response signals including RSSI measurements and data corresponding to the encrypted data in response to the LF signal (S20).

Through the foregoing operations S10 and S20, the smart key controller 20 determines whether the smart key 1 located within the reference distance from the vehicle is an authenticated smart key 1 (S30). When the data included in the RF response signal is data corresponding to a previously registered smart key 1, the detected smart key 1 is determined as the authenticated smart key 1.

When the authenticated smart key 1 is detected, the smart key controller 20 sends the LF signal including the RSSI information and the data for identification to the detected smart key 1 (S40).

That is, in this embodiment, the smart key controller 20 sends the LF signal of data including minimum information for identifying the smart key 1, instead of continuously sending the LF signal including the encrypted data, after the authenticated smart key 1 is detected, thereby reducing the sending frequency of LF signal.

Then, the smart key controller 20 receives the RF response signal including the RSSI measurements in response to the LF signal (S50).

That is, in this embodiment, the smart key controller 20 receives the RF response signal including only the RSSI measurements from the smart key 1, thereby significantly reducing the time taken in sending and receiving the signal for detecting the location of the smart key 1.

Next, the smart key controller 20 determines whether the smart key 1 is present within the reference distance from the vehicle (S60), and sends the LF signal again by returning to operation S40 of sending the LF signal when the authenticated smart key 1 is present.

That is, after the authenticated smart key 1 located within the reference distance from the vehicle is detected, operations S40 and S50 of detecting the location of the smart key 1 are repeated until the smart key 1 moves away the reference distance from the vehicle, thereby accurately determining the location of the smart key 1.

In addition, according to one embodiment, the smart key controller 20 may send LF signal additionally including masking information for specifying a smart key 1 such that only the detected authenticated smart key 1 can issue a response after the authenticated smart key 1 is detected, thereby minimizing the communicating frequency of signals with the smart key 1.

Therefore, the smart key controller 20 sends the LF signal and then sends the LF signal including the RSSI information, the data for identification and the masking information again when the predetermined reference time has elapsed, thereby reducing the sending frequency of signals.

The reference time refers to time taken until the smart key 1 sends the RF response signal from time of receiving the LF signal, and may vary depending upon the reference distance, i.e. a communicative distance between the smart key 1 and the smart key controller 20.

Further, in this embodiment, the smart key controller 20 may send the LF signal including the RSSI information, the data for identification and the masking information again when the RF response signal is received from the smart key 1 corresponding to the masking information even before the reference time elapses.

According to the embodiments of the present invention, time taken in sending and receiving a signal for detecting a location of a smart key is minimized, whereby a path of the smart key can be more accurately detected.

Further, according to the embodiments of the present invention, correct execution of a subsequent control command can be achieved by correctly determining a driver intention about whether to enter or pass by a vehicle based on accurate detection of the path of the smart key.

Although some embodiments have been described herein, it should be understood by those skilled in the art that these embodiments are given by way of illustration only, and that various modifications, variations, and alterations can be made without departing from the spirit and scope of the invention. Therefore, the scope of the invention should be limited only by the accompanying claims and equivalents thereof.

Claims

WHAT IS CLAIMED IS:

1. A method for detecting a location of a smart key, comprising

detecting, by a smart key controller, a smart key located within a reference distance from a vehicle;

when an authenticated smart key located within the reference distance from the vehicle is detected, sending an LF (Low frequency) signal including RSSI (Received Signal Strength Indication) information and data for identification to the detected smart key; and

receiving an RF (radio frequency) response signal including RSSI measurements in response to the LF signal.

2. The method according to claim 1, wherein detecting a smart key located within a reference distance from a vehicle comprises:

sending an LF signal including RSSI information and encrypted data to surrounding regions of the vehicle; and

receiving an RF response signal including RSSI measurements and data corresponding to the encrypted data in response to the LF signal.

3. The method according to claim 2, wherein the data for identification comprises data including information for the smart key controller to identify a smart key, and the encrypted data comprises data including information for the smart key controller to perform an authentication procedure with regard to the smart key.

4. The method according to any one of claims 1 to 3, wherein, in sending the LF signal, the smart key controller sends the LF signal including masking information for specifying a smart key such that only the detected smart key can issue a response.

5. The method according to claim 4, further comprising: returning to sending the LF signal when a predetermined reference time has elapsed after sending the LF signal.

6. The method according to claim 5, further comprising: returning to sending the LF signal when the RF response signals are received from the authenticated smart key before the predetermined reference time has elapsed.

7. The method according to any one of claims 1 to 6, further comprising:

determining whether the authenticated smart key is present within the reference distance from the vehicle after receiving the RF response signals; and

returning to sending the LF signal when the authenticated smart key is present within the reference distance.

8. An apparatus for detecting a location of a smart key, comprising:

a communication unit for communicating with the smart key; and

a smart key controller for sending an LF (Low frequency) signal including RSSI (Received Signal Strength Indication) information and data for identification to a detected authenticated smart key and for receiving an RF (radio frequency) response signal including RSSI measurements through the communication unit when the authenticated smart key located within a reference distance from a vehicle is detected through the communication unit.

9. The apparatus according to claim 8, wherein the authenticated smart key located within the reference distance from the vehicle is detected as the communication unit sends an LF signal including RSSI information and encrypted data to surrounding regions of the vehicle and receives RF response signals including RSSI measurements and data corresponding to the encrypted data in response to the LF signal.

10. The apparatus according to claim 8 or claim 9, wherein the smart key controller is adapted to send an LF signal including masking information for specifying a smart key such that only the detected smart key can issue a response.